This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A291737 #4 Sep 11 2017 20:05:22 %S A291737 1,2,5,11,25,54,121,267,591,1310,2899,6422,14218,31486,69722,154389, %T A291737 341881,757050,1676405,3712200,8220236,18202762,40307892,89257156, %U A291737 197649588,437672056,969173912,2146123007,4752340053,10523504828,23303078705,51601960101 %N A291737 p-INVERT of (1,0,1,0,0,0,0,...), where p(S) = 1 - S - S^2 - S^3. %C A291737 Suppose s = (c(0), c(1), c(2), ...) is a sequence and p(S) is a polynomial. Let S(x) = c(0)*x + c(1)*x^2 + c(2)*x^3 + ... and T(x) = (-p(0) + 1/p(S(x)))/x. The p-INVERT of s is the sequence t(s) of coefficients in the Maclaurin series for T(x). Taking p(S) = 1 - S gives the "INVERT" transform of s, so that p-INVERT is a generalization of the "INVERT" transform (e.g., A033453). %C A291737 See A291728 for a guide to related sequences. %H A291737 Clark Kimberling, <a href="/A291737/b291737.txt">Table of n, a(n) for n = 0..1000</a> %H A291737 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (1, 1, 2, 2, 3, 1, 3, 0, 1) %F A291737 G.f.: -(((1 + x^2) (1 - x + x^2) (1 + 2 x + 2 x^2 + x^3 + x^4))/(-1 + x + x^2 + 2 x^3 + 2 x^4 + 3 x^5 + x^6 + 3 x^7 + x^9)). %F A291737 a(n) = a(n-1) + a(n-2) + 2*a(n-3) + 2*a(n-4) + 3*a(n-5) + a(n-6) + 3*a(n-7) + a(n-9) for n >= 10. %t A291737 z = 60; s = x + x^3; p = 1 - s - s^2 - s^3; %t A291737 Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A154272 *) %t A291737 Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A291737 *) %Y A291737 Cf. A154272, A291728. %K A291737 nonn,easy %O A291737 0,2 %A A291737 _Clark Kimberling_, Sep 11 2017